Oops! Yes, of course it was April 16 and not May 16. Actually, that may be the first mistake I've made this year.

excerpts from Magruder's report:

HEADQUARTERS DEPARTMENT OF THE PENINSULA, Lee's Farm, Va., May 3, 1862.
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After eleven days of examination the enemy seems very properly to have arrived at the conclusion that Dam Numbers 1, the center of our line, was the weakest point in it, and hence, on April 16, he made what seems to have been a serious effort to break through at that point. Early on that morning he opened at that dam a most furious attack of artillery, filling the woods with shells, while his sharpshooters pressed forward close to our lines. From 9 a. m. to 12 m. six pieces were kept in constant fire against us, and by 3 p. m. nearly three batteries were directing a perfect storm of shot and shell on our exposed position. We had only three pieces in position at that point, but two of them could not be used with effect and were rarely fired, so that we were constrained to reply with only one 6-pounder of the Troup Artillery, Cobb's (Georgia) Legion, Captain M. Stanley, under the particular charge of
Lieutenant Pope. This piece was served with the greatest accuracy and effect,
and by the coolness and skill with which it was handled the great odds against us were almost counterbalanced.
By 3.30 p. m., the intensity of the cannonading increasing, heavy masses of
infantry commenced to deploy in our front and a heavy musketry fire was opened upon us. Under the cover of this continuous stream of fire an effort was made by the enemy to throw forces over the stream and storm our 6-pounder battery, which was inflicting such damage upon them. This charge was very rapid and vigorous, and before our men were prepared to receive it several companies of a Vermont regiment succeeded in getting across and occupying the rifle pits of the Fifteenth North Carolina Volunteers, who were some hundred yards to the rear, throwing up a work for the protection of their camp. This regiment immediately sprang to arms and engaged the enemy with spirit, under the lead of their brave but unfortunate commander, [Robert M.] McKinney, and, aided by the Sixteenth Georgia Regiment, repulsed the enemy, but when the gallant McKinney fell a temporary confusion ensued, which was increased by an unauthorized order
to fall back. The enemy renewed the attack with great force. At this moment the Seventh and Eighth Georgia, under command of Colonels Wilson and Lamar, respectively, the left of the Sixteenth Georgia, under command of Colonel Goode Bryan, and the two companies of Captains Martin and Burke, of the Second Louisiana, under Colonel [J. T.] Norwood, accompanied by the Fifteenth North Carolina, with fixed bayonets and the steadiness of veterans, charged the rifle pits and drove the enemy from them with great slaughter.
Colonel Anderson, commanding his brigade, and the commanding officers of the troops above mentioned, deserve great praise for the promptness with which they rushed to the conflict and repelled this serious attempt of the enemy. Subsequently the enemy massed heavier bodies of troops and again approached the stream. It was evident that a most serious and energetic attack in large force was being made to break our center, under, it is believed, the immediate eye of McClellan himself, but Brigadier General Howell Cobb, who was in command at that point, forming the Second Louisiana, Seventh and Eighth Georgia, of Colonel [George T.] Anderson's brigade; the Fifteenth North Carolina, Twenty-fourth Georgia, and Cobb's Legion, in line of battle on our front, received the attack with great firmness, and the enemy recoiled with loss from the steady fire of our troops before reaching the middle of the water. Brigadier-General McLaws, commanding the Second Division (of which Cobb's command formed a part), hearing the serious firing, hastened to the scene of action, and exhibited great coolness and judgment in his arrangements. The Tenth Louisiana, Fifteenth Virginia, a part of the Seventeenth Mississippi, and the Eleventh Alabama were ordered up as reserves, and were placed in position, the Tenth Louisiana marching to its place with the accuracy of a parade drill. The other regiments were assigned positions out of the range of fire. In addition, General McLaws placed the whole of his division under arms, ready to move as circumstances might require. Colonel Anderson had led two of his regiments, the Seventh and Eighth Georgia, into action and held two others in reserve, while Brigadier-General Toombs advanced with his own brigade, under the immediate command of Brigadier-General Semmes, close to the scene of action, and by my order (having just arrived) placed two regiments of this brigade into action, retaining the rest as reserves. These dispositions and the enemy's suffering from his two repulses rendered our position perfectly secure. Darkness put an end to the contest.
The dispositions of General McLaws were skillfully made...........but I would fail to do my duty if I did not specially mention some particular instances. Brigadier-General Cobb, commanding at this point, exhibited throughout the day the greatest courage and skill
Brigadier-General Toombs had in the morning, by my order, detached from his division Colonel Anderson's brigade to support Brigadier-General Cobb, and late in the evening, when ordered forward by me, promptly and energetically led the remainder of this command, under fire, arriving just before the enemy ceased the vigor of his attack and in time to share its dangers. Brigadier General P. J. Semmes commanded Toombs' brigade, the latter being in command of the division, and showed his usual promptness and courage. Colonel William M. Levy, of the Second Louisiana Regiment, was the colonel commanding at Dam Numbers 1, and evinced judgment, courage, and high soldierly qualities in his conduct and arrangements, which I desire specially to commend

J. BANKHEAD MAGRUDER,
Major-General